Tubing catcher



R. A. WILSON TUBING CATCHER June 7, 1938.

Filed July 8, 1955 I 2 Sheets-Sheet RAwsL s l x Kim, 1 52 mm 13M.

Patented June 7, 1938 UNITED STATES PATENT OFFICE TUBING CATCHER 5 Claims.

The invention relates to a combination tubing anchor and catcher of the type to be employed upon a string of pipe being lowered and anchored into a well bore.

It is one of the objects of the invention to provide a tubing catcher mechanism which is capable of automatically setting itself in event the tubing should be dropped so as to catch the tubing and prevent excessive damage in the well bore.

Another object of the invention is to provide a combination tubing catcher and anchor so that the device serves as a tubing catcher in event of accident as the tubing is being lowered into the well and when the tubing is landed in its operative position the apparatus can then be set to serve as an anchor or support for the tubing.

Another object of the invention is to provide a tubing anchor which will support a portion of the weight of the string of tubing in order to eliminate an excessive stretch and stress on the string of tubing.

Other and further objects of the invention will be readily apparent when the following description is considered in connection with the accompanying drawings wherein:

Fig. 1 is a side elevation of the tubing catcher portion of the device, certain parts being shown in section and broken away in order to illustrate the construction thereof.

Fig. 2 is a viewsimilar to Fig. 1 showing the lower end of the apparatus and particularly the mechanism for setting the anchor in the well.

Figs. 3, 4, and 5 are sections taken on correspondingly numbered sectional lines on Fig. 1.

Fig. 6 is an assembly view showing the device set in position as a tubing anchor to support the string of tubing.

Fig. 7 is a section showing the arrangement of the beveled steps devised to eliminate the accumulation of parafiin.

Fig. 8 is a section taken on the line 8--8 of Fig. 6.

Fig. 9 is a section taken on the line 9--9 of Fig. 2.

The tool will be assembled as seen in Figs. 1 and 2 with its upper end connected to the string of tubing 3 which is to be lowered into the well, the connection to the tubing being made by the head 4 which is threaded to the tubing. This head dis in the form of a coupling having ratchet teeth 5 upon the outer face thereof. These teeth are provided so that in event the tool becomes loose in the hole it may be gripped by an. overshot or suitable fishing tool to effect its removal.

The coupling 4 is threaded at 6 to the upper end of the stem I. This stem is the principal supporting structure of the tubing catcher and is preferably made of seamless upset tubing. The upset or wedged portion of this stem is indicated at 8.. The coupling 4 is preferably welded at 9 to the upper end of the stem so that the connec-' tion is firm and secure in order to make certain that the head will not become loosened from the stem.

After these parts are assembled in this manner and fixed together the expander body I0 is cast about the lower end of the coupling 4 of the up per end of the stem 1 so that the swedged portion 8 is imbedded in the body of the expander. In this manner when. the load is applied to the expander in order to support the string of tubing 3 the swedged portion 8 of the stem serves as a shoulder to transfer the stresses from the stem to the expander body.

Particular attention is directed to the configuration of the expander body because of the provision of the grooves I-I one of which is positioned between each series of stepped faces l2. Each series of faces includes the upper face l3, the intermediate face I4, and the bottom face I5. These faces are offset from each other by the steps I6 and I1 so that the jaw I8 which cooperates with the series of steps can be. of sufficient length to distribute the unit area pressure on the inside of the casing 20, as best seen in Fig. 6. There have been instances where the jaws were of too small an area and when an enormous pressure was applied to them they wouldbe forced outwardly through the casing and, of course, the tubing catcher would be inoperative. With the advent of. longer strings of tubing the greater length jaws have been devised and in order to get a uniform expansion while fitting the apparatus into a small diameter casing it has been found that the cooperating stepped faces serve to permit a greater length of jaw which is uniformly supported in order to withstand the applied pressure.

When the device is in an inoperative position as seen in Fig. 1 the shoulder 2| on the upper end of the jaw I8 cooperates with the shoulder I6 and the shoulder 22 cooperates with the shoulder II in order to support the jaw. In other words, the jaw rides on these shoulders when it is in an inoperative or collapsed position. The shoulders I6 and H are preferably beveled at 25 away from the center so as to provide' an. outwardly and downwardly inclined surface. This inclined surface is provided so that parafiin and other foreign material settling down through the well casing will not accumulate on these faces and prevent movement of the jaws to collapsed position.

The bevel permits the particles to roll off the shoulder and in event there is an accumulation of material when the jaws are collapsed then the shoulder 2| in moving downwardly comes into engagement with the apex 25 of the shoulder face so that any accumulation of paraffin or other material on the shoulder is extruded because of the taper 25. This arrangement insures that the tubing catcher can be collapsed when it is necessary to remove the tubing.

In order that the jaw 18 may be held in sliding relationship with the body I!) a tongue and groove connection 28 is provided on the upper face l3. It has been found unnecessary to provide this tongue and groove construction on the faces I 3 and i5 because the upper connection tends to hold the jaw in proper position.

The actuating mechanism for the jaws l8 consists of a toggle link 38 which is pinned to the lower end of the jaw H! by the pin 3| which passes through the ears 32 of the jaw and through the upper end of the toggle link 30. The lower end of the toggle link 38 has a crosshead 33 thereon as best seen in Fig. 5 and this crosshead fits in a slot 34 which merges with the opening 35 both of which are formed in the upper end of the weight member 36. In order to assemble the device it is only necessary to slip the head 33 into the groove 34 and then slip the weight member over the stem 1 so that the head 33 is secured against removal from the slot 34 because of the presence of the stem. This is a feature of advantage in devices of this type because it is advisable to have few loose or independent parts which may become loosened or broken and fall into the well. With this integral construction as shown the link 30 is securely anchored in position for pivoting movement and cannot be displaced.

The Weight 36 is slidable with respect to the stem 1 and is supported upon a'coil spring 38 which abuts against the collar 39 attached to the lower end of the stem 1. The upper end of this spring 38 abuts against a shoulder 40 on the inside of the weight 36 so that the weight is floating on the spring. The weight is preferably streamlined as seen in Fig. 6 with the lower end 4! of the leg member 42 being tapered. Where the leg member joins the main body of the weight the body is also tapered at 43 so that there will be no projecting portions which will serve as obstructions to the flow of fluid as the device is being lowered through the fluid into the well. It has been found that where the device is properly balanced on the spring 38 that obstructions or shoulders on the weight member are unnecessary because the weight member will preferably act of its own inertia when the tubing is dropped sharply, and that the tubing catcher can be lowered at a faster rate if it is stream-lined than where projecting shoulders are contacted by the fluid. On the other hand, when it is balanced the tubing catcher is much more sensitive and where a tubing has been dropped the catcher has operated to grip the casing and stop the movement of the tubing after it has dropped but six inches.

The stream-lining of the weight permits a flow of fluid upwardly past the tubing catcher when such a flow is desired.

In combination with the tubing catcher just described is the mechanism for effecting the starting of the catcher when it is to be used as a tubing anchor. This mechanism is connected to the coupling 39 and includes the anchor stem 58. This stem has telescoped thereover a ring 5| which carries a plurality of downwardly extending fingers 52. These fingers are of considerable length and may have an internal ring 53 holding the lower'ends thereof together. These fingers tend to center the device about the stem 58 in combination with the spring arms 55. These spring arms are fastened at 55 to the ring 5| but their lower ends are attached to a ring 5'! which is just beyond the lower end of the fingers 52 and is detached therefrom. In this manner as the springs 55 are compressed or expanded there will be a slight longitudinal movement of the ring 51 to compensate for the radial contraction or expansion. The lower end of the fingers 52 are slotted at 58 to permit the proper positioning of the spring arms 55.

As seen in Fig. 6 a guide slot 60 is provided between the fingers 52 and this slot is in the form of an inverted J with the short leg at El and the long leg at 62. Disposed in this slot is a stud 63 which is affixed to the coupling 39. The purpose of this stud is to prevent this anchoring device from moving upwardly while the tool is being lowered into the well as a tubing catcher. v

When the tool is to be lowered into the well the stud 63 will be positioned in the short leg 6| of the slot so that this anchor cannot move upwardly to set the slips or jaws !8 but will be prevented from this movement because the stud 63 engages the lower end of the slot 6|. In this manner the anchor will not interfere with the operation of the tubing catcher as the string is being lowered into position. When, however, the tubing has been moved downwardly to the proper elevation and it is desired to anchor the lower end so as to absorb part of the weight of the string of pipe and eliminate the stretch thereof, then the tool will be raised slightly. The spring arms 55 are, of course, rubbing against the inside of the casing and this friction will hold the anchor sleeve against upward movement so that the stud 63 will move upwardly into the slot 6|. A slight rotation of the string of pipe 3 causes the stud to move over into alignment with the long slot 62. As the device is lowered slightly this stud 63 will pass downwardly in the slot 62 so as to allow the upper end 10 of the anchor to engage the lower end H of the weight 36. The friction of the arms 55 causes this to drag and if lowering of the tool is continued then the weight 36 is pushed upward and the jaws [8 are caused to move outwardly and grip the casing.

By proper adjustment of the elevation where the anchor sleeve is to be unlatched the desired amount of stretch can be removed from the string of tubing and any desired portion of the weight can in this manner be supported on this anchor tool and transferred from the tubing to the casing. When it is desired to remove the tubing it is only necessary to pull upwardly on the string of pipe and the stud 63 will then move upwardly in the slot 62 and the weight 38 will be free to drop back to its floating position on the spring 38 and carry with it the jaws I8. The tongue and groove construction also maintains movement of the jaws sothat they cannot drop outwardly or become displaced and the entire device is collapsed so that the tubing may be readily removed from the hole by merely lifting thereon.

The lower end of the stem 50 is provided with the spider 16 which serves to center the tool so that there will be an even frictional engage-.-

ment of the arms 55 against the inside of the l casing.

All of the parts have been constructed and designed in order to avoid excessive frictional engagement with the fluid through which the tool is passing and the exposed surfaces are beveled so that there will be little if any deposit of foreign material thereon which might interfere with the operation of the too-l when it is being lowered into the well or removed therefrom.

What is claimed is:

1. A tubing catcher including a stem, said stem having a thickened end portion which merges into the adjacent portions of the stem through a shoulder, a coupling member threaded onto said thickened portion and forming a second shoulder, an expander body cast on said stem and enclosing said shoulders to transmit the load from said expander to said coupling, jaws arranged to be expanded by said expander body, and means on said stem for causing expansion of said jaws when the catcher is dropped.

2. In a tubing catcher, an expander body, jaws slidable thereon, shoulders on said jaws and said body to limit retractive movement of said jaws, the abutting surfaces of said shoulders being inclined with respect to each other throughout the major portions of their areas so as to lessen the resistance offered to retraction of the jaws by accumulations of paraflin and sand on said surfaces.

3. In a catcher for well tubing, a stem for attachment to the tubing, an expander body on said stem, jaws slidab-ly mounted on said expander, a weight on said stem below said jaws, said weight having T-slots in the walls thereof, and links attached to said jaws and having crossheads removably positioned within said slots,

the cross portion of said slots being elongated to allow vertical movement of said crosshead so that vibration of said weight is not transmitted to said jaws.

4. A combined catcher and anchor for a well tubing comprising, a stem for attachment to the tubing, an expander body on said stem, jaws slidably mounted on said expander body, a weight on said stem below said body and operatively connected to said jaws, spaced rings slidably mounted on said stem below said weight, do-wn wardly extending fingers attached to the uppermost of said rings, a plurality of bowed springs attached to said rings, said springs and fingers being so constructed and arranged that the anchor is centered thereby, and means for releasably connecting the spring and finger assembly to the stem whereby the spring and finger as- .sembly is held out of engagement with said weight until the connecting means is released.

5. A tubing catcher comprising a stem, said stern having a thickened end portion which merges into the adjacent portion of the stem through a shoulder, a coupling member threaded ontosaid thickened portion and forming a second shoulder, a stepped expander member on said stem and enclosing said shoulders, said ex pander member having three outwardly and upwardly inclined faces, each of said faces being formed in three segments so that a set of faces comprises three segments in a vertical. line, a jaw for each set of faces, each jaw having a cooperating set of faces so that relative .vertical movement between said expander and jaw effects lateral movement of the jaw, and a bypass area for fluid between adjacent segments.

ROBERT A. WILSON. 

